1 /*
2 * Copyright (c) 2018, 2024, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "cds/aotClassInitializer.hpp"
27 #include "cds/archiveBuilder.hpp"
28 #include "cds/archiveHeapLoader.hpp"
29 #include "cds/archiveHeapWriter.hpp"
30 #include "cds/archiveUtils.hpp"
31 #include "cds/cdsAccess.hpp"
32 #include "cds/cdsConfig.hpp"
33 #include "cds/cdsEnumKlass.hpp"
34 #include "cds/cdsHeapVerifier.hpp"
35 #include "cds/heapShared.hpp"
36 #include "cds/metaspaceShared.hpp"
37 #include "classfile/classLoaderData.hpp"
38 #include "classfile/classLoaderExt.hpp"
39 #include "classfile/javaClasses.inline.hpp"
40 #include "classfile/modules.hpp"
41 #include "classfile/stringTable.hpp"
42 #include "classfile/symbolTable.hpp"
43 #include "classfile/systemDictionary.hpp"
44 #include "classfile/systemDictionaryShared.hpp"
45 #include "classfile/vmClasses.hpp"
46 #include "classfile/vmSymbols.hpp"
47 #include "gc/shared/collectedHeap.hpp"
48 #include "gc/shared/gcLocker.hpp"
49 #include "gc/shared/gcVMOperations.hpp"
50 #include "logging/log.hpp"
51 #include "logging/logStream.hpp"
52 #include "memory/iterator.inline.hpp"
53 #include "memory/resourceArea.hpp"
54 #include "memory/universe.hpp"
55 #include "oops/compressedOops.inline.hpp"
56 #include "oops/fieldStreams.inline.hpp"
57 #include "oops/objArrayOop.inline.hpp"
58 #include "oops/oop.inline.hpp"
59 #include "oops/typeArrayOop.inline.hpp"
60 #include "prims/jvmtiExport.hpp"
61 #include "runtime/arguments.hpp"
62 #include "runtime/fieldDescriptor.inline.hpp"
63 #include "runtime/init.hpp"
64 #include "runtime/javaCalls.hpp"
65 #include "runtime/mutexLocker.hpp"
66 #include "runtime/safepointVerifiers.hpp"
67 #include "utilities/bitMap.inline.hpp"
68 #include "utilities/copy.hpp"
69 #if INCLUDE_G1GC
70 #include "gc/g1/g1CollectedHeap.hpp"
71 #endif
72
73 #if INCLUDE_CDS_JAVA_HEAP
74
75 struct ArchivableStaticFieldInfo {
76 const char* klass_name;
77 const char* field_name;
78 InstanceKlass* klass;
79 int offset;
80 BasicType type;
81
82 ArchivableStaticFieldInfo(const char* k, const char* f)
83 : klass_name(k), field_name(f), klass(nullptr), offset(0), type(T_ILLEGAL) {}
84
85 bool valid() {
86 return klass_name != nullptr;
87 }
88 };
89
90 class HeapShared::ArchivingObjectMark : public StackObj {
91 public:
92 ArchivingObjectMark(oop obj) {
93 _trace->push(obj);
94 }
95 ~ArchivingObjectMark() {
96 _trace->pop();
97 }
98 };
99
100 class HeapShared::ContextMark : public StackObj {
101 ResourceMark rm;
102 public:
103 ContextMark(const char* c) : rm{} {
104 _context->push(c);
105 }
106 ~ContextMark() {
107 _context->pop();
108 }
109 };
110
111 bool HeapShared::_disable_writing = false;
112 DumpedInternedStrings *HeapShared::_dumped_interned_strings = nullptr;
113
114 size_t HeapShared::_alloc_count[HeapShared::ALLOC_STAT_SLOTS];
115 size_t HeapShared::_alloc_size[HeapShared::ALLOC_STAT_SLOTS];
116 size_t HeapShared::_total_obj_count;
117 size_t HeapShared::_total_obj_size;
118
119 #ifndef PRODUCT
120 #define ARCHIVE_TEST_FIELD_NAME "archivedObjects"
121 static Array<char>* _archived_ArchiveHeapTestClass = nullptr;
122 static const char* _test_class_name = nullptr;
123 static Klass* _test_class = nullptr;
124 static const ArchivedKlassSubGraphInfoRecord* _test_class_record = nullptr;
125 #endif
126
127
128 //
129 // If you add new entries to the following tables, you should know what you're doing!
130 //
131
132 static ArchivableStaticFieldInfo archive_subgraph_entry_fields[] = {
133 {"java/lang/Integer$IntegerCache", "archivedCache"},
134 {"java/lang/Long$LongCache", "archivedCache"},
135 {"java/lang/Byte$ByteCache", "archivedCache"},
136 {"java/lang/Short$ShortCache", "archivedCache"},
137 {"java/lang/Character$CharacterCache", "archivedCache"},
138 {"java/util/jar/Attributes$Name", "KNOWN_NAMES"},
139 {"sun/util/locale/BaseLocale", "constantBaseLocales"},
140 {"jdk/internal/module/ArchivedModuleGraph", "archivedModuleGraph"},
141 {"java/util/ImmutableCollections", "archivedObjects"},
142 {"java/lang/ModuleLayer", "EMPTY_LAYER"},
143 {"java/lang/module/Configuration", "EMPTY_CONFIGURATION"},
144 {"jdk/internal/math/FDBigInteger", "archivedCaches"},
145 {"java/lang/reflect/Proxy$ProxyBuilder", "archivedData"}, // FIXME -- requires AOTClassLinking
146
147 #ifndef PRODUCT
148 {nullptr, nullptr}, // Extra slot for -XX:ArchiveHeapTestClass
149 #endif
150 {nullptr, nullptr},
151 };
152
153 // full module graph
154 static ArchivableStaticFieldInfo fmg_archive_subgraph_entry_fields[] = {
155 {"jdk/internal/loader/ArchivedClassLoaders", "archivedClassLoaders"},
156 {ARCHIVED_BOOT_LAYER_CLASS, ARCHIVED_BOOT_LAYER_FIELD},
157 {"java/lang/Module$ArchivedData", "archivedData"},
158 {nullptr, nullptr},
159 };
160
161 KlassSubGraphInfo* HeapShared::_default_subgraph_info;
162 ArchivedKlassSubGraphInfoRecord* HeapShared::_runtime_default_subgraph_info;
163 GrowableArrayCHeap<OopHandle, mtClassShared>* HeapShared::_pending_roots = nullptr;
164 GrowableArrayCHeap<oop, mtClassShared>* HeapShared::_trace = nullptr;
165 GrowableArrayCHeap<const char*, mtClassShared>* HeapShared::_context = nullptr;
166 GrowableArrayCHeap<OopHandle, mtClassShared>* HeapShared::_root_segments;
167 int HeapShared::_root_segment_max_size_elems;
168 OopHandle HeapShared::_scratch_basic_type_mirrors[T_VOID+1];
169 MetaspaceObjToOopHandleTable* HeapShared::_scratch_java_mirror_table = nullptr;
170 MetaspaceObjToOopHandleTable* HeapShared::_scratch_references_table = nullptr;
171
172 static bool is_subgraph_root_class_of(ArchivableStaticFieldInfo fields[], InstanceKlass* ik) {
173 for (int i = 0; fields[i].valid(); i++) {
174 if (fields[i].klass == ik) {
175 return true;
176 }
177 }
178 return false;
179 }
180
181 bool HeapShared::is_subgraph_root_class(InstanceKlass* ik) {
182 return is_subgraph_root_class_of(archive_subgraph_entry_fields, ik) ||
183 is_subgraph_root_class_of(fmg_archive_subgraph_entry_fields, ik);
184 }
185
186 unsigned HeapShared::oop_hash(oop const& p) {
187 // Do not call p->identity_hash() as that will update the
188 // object header.
189 return primitive_hash(cast_from_oop<intptr_t>(p));
190 }
191
192 static void reset_states(oop obj, TRAPS) {
193 Handle h_obj(THREAD, obj);
194 InstanceKlass* klass = InstanceKlass::cast(obj->klass());
195 TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates");
196 Symbol* method_sig = vmSymbols::void_method_signature();
197
198 while (klass != nullptr) {
199 Method* method = klass->find_method(method_name, method_sig);
200 if (method != nullptr) {
201 assert(method->is_private(), "must be");
202 if (log_is_enabled(Debug, cds)) {
203 ResourceMark rm(THREAD);
204 log_debug(cds)(" calling %s", method->name_and_sig_as_C_string());
205 }
206 JavaValue result(T_VOID);
207 JavaCalls::call_special(&result, h_obj, klass,
208 method_name, method_sig, CHECK);
209 }
210 klass = klass->java_super();
211 }
212 }
213
214 void HeapShared::reset_archived_object_states(TRAPS) {
215 assert(CDSConfig::is_dumping_heap(), "dump-time only");
216 log_debug(cds)("Resetting platform loader");
217 reset_states(SystemDictionary::java_platform_loader(), CHECK);
218 log_debug(cds)("Resetting system loader");
219 reset_states(SystemDictionary::java_system_loader(), CHECK);
220
221 // Clean up jdk.internal.loader.ClassLoaders::bootLoader(), which is not
222 // directly used for class loading, but rather is used by the core library
223 // to keep track of resources, etc, loaded by the null class loader.
224 //
225 // Note, this object is non-null, and is not the same as
226 // ClassLoaderData::the_null_class_loader_data()->class_loader(),
227 // which is null.
228 log_debug(cds)("Resetting boot loader");
229 JavaValue result(T_OBJECT);
230 JavaCalls::call_static(&result,
231 vmClasses::jdk_internal_loader_ClassLoaders_klass(),
232 vmSymbols::bootLoader_name(),
233 vmSymbols::void_BuiltinClassLoader_signature(),
234 CHECK);
235 Handle boot_loader(THREAD, result.get_oop());
236 reset_states(boot_loader(), CHECK);
237 }
238
239 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = nullptr;
240
241 bool HeapShared::has_been_archived(oop obj) {
242 assert(CDSConfig::is_dumping_heap(), "dump-time only");
243 return archived_object_cache()->get(obj) != nullptr;
244 }
245
246 int HeapShared::append_root(oop obj) {
247 assert(CDSConfig::is_dumping_heap(), "dump-time only");
248
249 // No GC should happen since we aren't scanning _pending_roots.
250 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
251
252 if (_pending_roots == nullptr) {
253 _pending_roots = new GrowableArrayCHeap<OopHandle, mtClassShared>(500);
254 }
255
256 OopHandle oh(Universe::vm_global(), obj);
257 return _pending_roots->append(oh);
258 }
259
260 objArrayOop HeapShared::root_segment(int segment_idx) {
261 if (CDSConfig::is_dumping_heap() && !CDSConfig::is_dumping_final_static_archive()) {
262 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
263 if (!HeapShared::can_write()) {
264 return nullptr;
265 }
266 } else {
267 assert(CDSConfig::is_using_archive(), "must be");
268 }
269
270 objArrayOop segment = (objArrayOop)_root_segments->at(segment_idx).resolve();
271 assert(segment != nullptr, "should have been initialized");
272 return segment;
273 }
274
275 inline unsigned int oop_handle_hash(const OopHandle& oh) {
276 oop o = oh.resolve();
277 if (o == nullptr) {
278 return 0;
279 } else {
280 return o->identity_hash();
281 }
282 }
283
284 inline bool oop_handle_equals(const OopHandle& a, const OopHandle& b) {
285 return a.resolve() == b.resolve();
286 }
287
288 class OrigToScratchObjectTable: public ResourceHashtable<OopHandle, OopHandle,
289 36137, // prime number
290 AnyObj::C_HEAP,
291 mtClassShared,
292 oop_handle_hash,
293 oop_handle_equals> {};
294
295 static OrigToScratchObjectTable* _orig_to_scratch_object_table = nullptr;
296
297 void HeapShared::track_scratch_object(oop orig_obj, oop scratch_obj) {
298 MutexLocker ml(ArchivedObjectTables_lock, Mutex::_no_safepoint_check_flag);
299 if (_orig_to_scratch_object_table == nullptr) {
300 _orig_to_scratch_object_table = new (mtClass)OrigToScratchObjectTable();
301 }
302
303 OopHandle orig_h(Universe::vm_global(), orig_obj);
304 OopHandle scratch_h(Universe::vm_global(), scratch_obj);
305 _orig_to_scratch_object_table->put_when_absent(orig_h, scratch_h);
306 }
307
308 oop HeapShared::orig_to_scratch_object(oop orig_obj) {
309 MutexLocker ml(ArchivedObjectTables_lock, Mutex::_no_safepoint_check_flag);
310 if (_orig_to_scratch_object_table != nullptr) {
311 OopHandle orig(&orig_obj);
312 OopHandle* v = _orig_to_scratch_object_table->get(orig);
313 if (v != nullptr) {
314 return v->resolve();
315 }
316 }
317 return nullptr;
318 }
319
320 // Permanent oops are used to support AOT-compiled methods, which may have in-line references
321 // to Strings and MH oops.
322 //
323 // At runtime, these oops are stored in _runtime_permanent_oops (which keeps them alive forever)
324 // and are accssed vis CDSAccess::get_archived_object(int).
325 struct PermanentOopInfo {
326 int _index; // Gets assigned only if HeapShared::get_archived_object_permanent_index() has been called on the object
327 int _heap_offset; // Offset of the object from the bottom of the archived heap.
328 PermanentOopInfo(int index, int heap_offset) : _index(index), _heap_offset(heap_offset) {}
329 };
330
331 class PermanentOopTable: public ResourceHashtable<OopHandle, PermanentOopInfo,
332 36137, // prime number
333 AnyObj::C_HEAP,
334 mtClassShared,
335 oop_handle_hash,
336 oop_handle_equals> {};
337
338 static int _dumptime_permanent_oop_count = 0;
339 static PermanentOopTable* _dumptime_permanent_oop_table = nullptr;
340 static GrowableArrayCHeap<OopHandle, mtClassShared>* _runtime_permanent_oops = nullptr;
341
342 // ArchiveHeapWriter adds each archived heap object to _dumptime_permanent_oop_table,
343 // so we can remember their offset (from the bottom of the archived heap).
344 void HeapShared::add_to_permanent_oop_table(oop obj, int offset) {
345 assert_at_safepoint();
346 if (_dumptime_permanent_oop_table == nullptr) {
347 _dumptime_permanent_oop_table = new (mtClass)PermanentOopTable();
348 }
349
350 PermanentOopInfo info(-1, offset);
351 OopHandle oh(Universe::vm_global(), obj);
352 _dumptime_permanent_oop_table->put_when_absent(oh, info);
353 }
354
355 // A permanent index is assigned to an archived object ONLY when
356 // the AOT compiler calls this function.
357 int HeapShared::get_archived_object_permanent_index(oop obj) {
358 MutexLocker ml(ArchivedObjectTables_lock, Mutex::_no_safepoint_check_flag);
359
360 if (!CDSConfig::is_dumping_heap()) {
361 return -1; // Called by the Leyden old workflow
362 }
363 if (_dumptime_permanent_oop_table == nullptr) {
364 return -1;
365 }
366
367 if (_orig_to_scratch_object_table != nullptr) {
368 OopHandle orig(&obj);
369 OopHandle* v = _orig_to_scratch_object_table->get(orig);
370 if (v != nullptr) {
371 obj = v->resolve();
372 }
373 }
374
375 OopHandle tmp(&obj);
376 PermanentOopInfo* info = _dumptime_permanent_oop_table->get(tmp);
377 if (info == nullptr) {
378 return -1;
379 } else {
380 if (info->_index < 0) {
381 info->_index = _dumptime_permanent_oop_count++;
382 }
383 return info->_index;
384 }
385 }
386
387 oop HeapShared::get_archived_object(int permanent_index) {
388 assert(permanent_index >= 0, "sanity");
389 assert(ArchiveHeapLoader::is_in_use(), "sanity");
390 assert(_runtime_permanent_oops != nullptr, "sanity");
391
392 oop obj = _runtime_permanent_oops->at(permanent_index).resolve();
393 log_info(cds)("GET perm obj %d = %p", permanent_index, cast_from_oop<void*>(obj));
394 if (obj != nullptr) {
395 log_info(cds)("GET perm obj %d class = %p", permanent_index, obj->klass());
396 log_info(cds)("GET perm obj %d class = %s", permanent_index, obj->klass()->external_name());
397 }
398 return obj;
399 }
400
401 // Remember all archived heap objects that have a permanent index.
402 // table[i] = offset of oop whose permanent index is i.
403 void CachedCodeDirectoryInternal::dumptime_init_internal() {
404 const int count = _dumptime_permanent_oop_count;
405 int* table = (int*)CDSAccess::allocate_from_code_cache(count * sizeof(int));
406 for (int i = 0; i < count; i++) {
407 table[count] = -1;
408 }
409 _dumptime_permanent_oop_table->iterate([&](OopHandle o, PermanentOopInfo& info) {
410 int index = info._index;
411 if (index >= 0) {
412 assert(index < count, "sanity");
413 table[index] = info._heap_offset;
414 }
415 return true; // continue
416 });
417
418 for (int i = 0; i < count; i++) {
419 assert(table[i] >= 0, "must be");
420 }
421
422 log_info(cds)("Dumped %d permanent oops", count);
423
424 _permanent_oop_count = count;
425 CDSAccess::set_pointer(&_permanent_oop_offsets, table);
426 }
427
428 // This is called during the bootstrap of the production run, before any GC can happen.
429 // Record each permanent oop in a OopHandle for GC safety.
430 void CachedCodeDirectoryInternal::runtime_init_internal() {
431 int count = _permanent_oop_count;
432 int* table = _permanent_oop_offsets;
433 _runtime_permanent_oops = new GrowableArrayCHeap<OopHandle, mtClassShared>();
434 for (int i = 0; i < count; i++) {
435 oop obj = ArchiveHeapLoader::oop_from_offset(table[i]);
436 OopHandle oh(Universe::vm_global(), obj);
437 _runtime_permanent_oops->append(oh);
438
439 ResourceMark rm;
440 log_info(cds)("perm obj %d = %p", i, cast_from_oop<void*>(obj));
441 if (obj != nullptr) {
442 log_info(cds)("perm obj %d class = %p", i, obj->klass());
443 log_info(cds)("perm obj %d class = %s", i, obj->klass()->external_name());
444 }
445 }
446 };
447
448 void HeapShared::get_segment_indexes(int idx, int& seg_idx, int& int_idx) {
449 assert(_root_segment_max_size_elems > 0, "sanity");
450
451 // Try to avoid divisions for the common case.
452 if (idx < _root_segment_max_size_elems) {
453 seg_idx = 0;
454 int_idx = idx;
455 } else {
456 seg_idx = idx / _root_segment_max_size_elems;
457 int_idx = idx % _root_segment_max_size_elems;
458 }
459
460 assert(idx == seg_idx * _root_segment_max_size_elems + int_idx,
461 "sanity: %d index maps to %d segment and %d internal", idx, seg_idx, int_idx);
462 }
463
464 // Returns an objArray that contains all the roots of the archived objects
465 oop HeapShared::get_root(int index, bool clear) {
466 assert(index >= 0, "sanity");
467 assert(!CDSConfig::is_dumping_heap() && CDSConfig::is_using_archive(), "runtime only");
468 assert(!_root_segments->is_empty(), "must have loaded shared heap");
469 int seg_idx, int_idx;
470 get_segment_indexes(index, seg_idx, int_idx);
471 oop result = root_segment(seg_idx)->obj_at(int_idx);
472 if (clear) {
473 clear_root(index);
474 }
475 return result;
476 }
477
478 void HeapShared::clear_root(int index) {
479 assert(index >= 0, "sanity");
480 assert(CDSConfig::is_using_archive(), "must be");
481 if (ArchiveHeapLoader::is_in_use()) {
482 int seg_idx, int_idx;
483 get_segment_indexes(index, seg_idx, int_idx);
484 if (log_is_enabled(Debug, cds, heap)) {
485 oop old = root_segment(seg_idx)->obj_at(int_idx);
486 log_debug(cds, heap)("Clearing root %d: was " PTR_FORMAT, index, p2i(old));
487 }
488 root_segment(seg_idx)->obj_at_put(int_idx, nullptr);
489 }
490 }
491
492 bool HeapShared::archive_object(oop obj) {
493 assert(CDSConfig::is_dumping_heap(), "dump-time only");
494
495 assert(!obj->is_stackChunk(), "do not archive stack chunks");
496 if (has_been_archived(obj)) {
497 return true;
498 }
499
500 if (ArchiveHeapWriter::is_too_large_to_archive(obj->size())) {
501 log_debug(cds, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: " SIZE_FORMAT,
502 p2i(obj), obj->size());
503 debug_trace();
504 return false;
505 } else {
506 count_allocation(obj->size());
507 ArchiveHeapWriter::add_source_obj(obj);
508 CachedOopInfo info = make_cached_oop_info(obj);
509 archived_object_cache()->put_when_absent(obj, info);
510 archived_object_cache()->maybe_grow();
511 mark_native_pointers(obj);
512
513 if (log_is_enabled(Debug, cds, heap)) {
514 ResourceMark rm;
515 LogTarget(Debug, cds, heap) log;
516 LogStream out(log);
517 out.print("Archived heap object " PTR_FORMAT " : %s ",
518 p2i(obj), obj->klass()->external_name());
519 if (java_lang_Class::is_instance(obj)) {
520 Klass* k = java_lang_Class::as_Klass(obj);
521 if (k != nullptr) {
522 out.print("%s", k->external_name());
523 } else {
524 out.print("primitive");
525 }
526 }
527 out.cr();
528 }
529
530 if (java_lang_Module::is_instance(obj) && Modules::check_archived_module_oop(obj)) {
531 Modules::update_oops_in_archived_module(obj, append_root(obj));
532 }
533
534 return true;
535 }
536 }
537
538 class MetaspaceObjToOopHandleTable: public ResourceHashtable<MetaspaceObj*, OopHandle,
539 36137, // prime number
540 AnyObj::C_HEAP,
541 mtClassShared> {
542 public:
543 oop get_oop(MetaspaceObj* ptr) {
544 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
545 OopHandle* handle = get(ptr);
546 if (handle != nullptr) {
547 return handle->resolve();
548 } else {
549 return nullptr;
550 }
551 }
552 void set_oop(MetaspaceObj* ptr, oop o) {
553 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
554 OopHandle handle(Universe::vm_global(), o);
555 bool is_new = put(ptr, handle);
556 assert(is_new, "cannot set twice");
557 }
558 void remove_oop(MetaspaceObj* ptr) {
559 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
560 OopHandle* handle = get(ptr);
561 if (handle != nullptr) {
562 handle->release(Universe::vm_global());
563 remove(ptr);
564 }
565 }
566 };
567
568 void HeapShared::add_scratch_resolved_references(ConstantPool* src, objArrayOop dest) {
569 if (_scratch_references_table == nullptr) {
570 _scratch_references_table = new (mtClass)MetaspaceObjToOopHandleTable();
571 }
572 _scratch_references_table->set_oop(src, dest);
573 }
574
575 objArrayOop HeapShared::scratch_resolved_references(ConstantPool* src) {
576 return (objArrayOop)_scratch_references_table->get_oop(src);
577 }
578
579 void HeapShared::init_scratch_objects(TRAPS) {
580 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
581 BasicType bt = (BasicType)i;
582 if (!is_reference_type(bt)) {
583 oop m = java_lang_Class::create_basic_type_mirror(type2name(bt), bt, CHECK);
584 _scratch_basic_type_mirrors[i] = OopHandle(Universe::vm_global(), m);
585 track_scratch_object(Universe::java_mirror(bt), m);
586 }
587 }
588 _scratch_java_mirror_table = new (mtClass)MetaspaceObjToOopHandleTable();
589 if (_scratch_references_table == nullptr) {
590 _scratch_references_table = new (mtClass)MetaspaceObjToOopHandleTable();
591 }
592 }
593
594 // Given java_mirror that represents a (primitive or reference) type T,
595 // return the "scratch" version that represents the same type T.
596 // Note that if java_mirror will be returned if it's already a
597 // scratch mirror.
598 //
599 // See java_lang_Class::create_scratch_mirror() for more info.
600 oop HeapShared::scratch_java_mirror(oop java_mirror) {
601 assert(java_lang_Class::is_instance(java_mirror), "must be");
602
603 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
604 BasicType bt = (BasicType)i;
605 if (!is_reference_type(bt)) {
606 if (_scratch_basic_type_mirrors[i].resolve() == java_mirror) {
607 return java_mirror;
608 }
609 }
610 }
611
612 if (java_lang_Class::is_primitive(java_mirror)) {
613 return scratch_java_mirror(java_lang_Class::as_BasicType(java_mirror));
614 } else {
615 return scratch_java_mirror(java_lang_Class::as_Klass(java_mirror));
616 }
617 }
618
619 oop HeapShared::scratch_java_mirror(BasicType t) {
620 assert((uint)t < T_VOID+1, "range check");
621 assert(!is_reference_type(t), "sanity");
622 return _scratch_basic_type_mirrors[t].resolve();
623 }
624
625 oop HeapShared::scratch_java_mirror(Klass* k) {
626 return _scratch_java_mirror_table->get_oop(k);
627 }
628
629 void HeapShared::set_scratch_java_mirror(Klass* k, oop mirror) {
630 track_scratch_object(k->java_mirror(), mirror);
631 _scratch_java_mirror_table->set_oop(k, mirror);
632 }
633
634 void HeapShared::remove_scratch_objects(Klass* k) {
635 _scratch_java_mirror_table->remove_oop(k);
636 if (k->is_instance_klass()) {
637 _scratch_references_table->remove(InstanceKlass::cast(k)->constants());
638 }
639 oop mirror = k->java_mirror();
640 if (mirror != nullptr) {
641 OopHandle tmp(&mirror);
642 OopHandle* v = _orig_to_scratch_object_table->get(tmp);
643 if (v != nullptr) {
644 oop scratch_mirror = v->resolve();
645 java_lang_Class::set_klass(scratch_mirror, nullptr);
646 _orig_to_scratch_object_table->remove(tmp);
647 }
648 }
649 }
650
651 bool HeapShared::is_lambda_form_klass(InstanceKlass* ik) {
652 return ik->is_hidden() &&
653 (ik->name()->starts_with("java/lang/invoke/LambdaForm$MH+") ||
654 ik->name()->starts_with("java/lang/invoke/LambdaForm$DMH+") ||
655 ik->name()->starts_with("java/lang/invoke/LambdaForm$BMH+"));
656 }
657
658 bool HeapShared::is_lambda_proxy_klass(InstanceKlass* ik) {
659 return ik->is_hidden() && (ik->name()->index_of_at(0, "$$Lambda+", 9) > 0);
660 }
661
662 bool HeapShared::is_archivable_hidden_klass(InstanceKlass* ik) {
663 return CDSConfig::is_dumping_invokedynamic() && (is_lambda_form_klass(ik) || is_lambda_proxy_klass(ik));
664 }
665
666 void HeapShared::copy_aot_initialized_mirror(Klass* orig_k, oop orig_mirror, oop m) {
667 if (!orig_k->is_instance_klass()) {
668 return;
669 }
670 InstanceKlass* ik = InstanceKlass::cast(orig_k);
671
672 if (HeapShared::is_archivable_hidden_klass(ik)) {
673 // We can't rerun the <clinit> method of hidden classes as we don't save
674 // the classData, so we must archive its mirror in initialized state.
675 assert(ik->is_initialized(), "must be");
676 }
677
678 if (!ik->is_initialized() || !AOTClassInitializer::can_archive_initialized_mirror(ik)) {
679 return;
680 }
681
682 int nfields = 0;
683 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) {
684 if (fs.access_flags().is_static()) {
685 fieldDescriptor& fd = fs.field_descriptor();
686 int offset = fd.offset();
687 switch (fd.field_type()) {
688 case T_OBJECT:
689 case T_ARRAY:
690 m->obj_field_put(offset, orig_mirror->obj_field(offset));
691 break;
692 case T_BOOLEAN:
693 m->bool_field_put(offset, orig_mirror->bool_field(offset));
694 break;
695 case T_BYTE:
696 m->byte_field_put(offset, orig_mirror->byte_field(offset));
697 break;
698 case T_SHORT:
699 m->short_field_put(offset, orig_mirror->short_field(offset));
700 break;
701 case T_CHAR:
702 m->char_field_put(offset, orig_mirror->char_field(offset));
703 break;
704 case T_INT:
705 m->int_field_put(offset, orig_mirror->int_field(offset));
706 break;
707 case T_LONG:
708 m->long_field_put(offset, orig_mirror->long_field(offset));
709 break;
710 case T_FLOAT:
711 m->float_field_put(offset, orig_mirror->float_field(offset));
712 break;
713 case T_DOUBLE:
714 m->double_field_put(offset, orig_mirror->double_field(offset));
715 break;
716 default:
717 ShouldNotReachHere();
718 }
719 nfields ++;
720 }
721 }
722
723 java_lang_Class::set_class_data(m, java_lang_Class::class_data(orig_mirror));
724
725 // Class::reflectData use SoftReference, which cannot be archived. Set it
726 // to null and it will be recreated at runtime.
727 java_lang_Class::set_reflection_data(m, nullptr);
728
729 if (log_is_enabled(Info, cds, init)) {
730 ResourceMark rm;
731 log_debug(cds, init)("copied %3d field(s) in preinitialized mirror %s%s", nfields, ik->external_name(),
732 ik->is_hidden() ? " (hidden)" : "");
733 }
734
735 InstanceKlass* buffered_ik = ArchiveBuilder::current()->get_buffered_addr(ik);
736 buffered_ik->set_has_preinitialized_mirror();
737 }
738
739 static void copy_java_mirror_hashcode(oop orig_mirror, oop scratch_m) {
740 int src_hash = orig_mirror->identity_hash();
741 scratch_m->set_mark(markWord::prototype().copy_set_hash(src_hash));
742 assert(scratch_m->mark().is_unlocked(), "sanity");
743
744 DEBUG_ONLY(int archived_hash = scratch_m->identity_hash());
745 assert(src_hash == archived_hash, "Java mirror wrong hash: original %x, scratch %x", src_hash, archived_hash);
746 }
747
748 void HeapShared::archive_java_mirrors() {
749 AOTClassInitializer::reset_preinit_check();
750
751 _orig_to_scratch_object_table->iterate([&](OopHandle o, OopHandle s) {
752 copy_java_mirror_hashcode(o.resolve(), s.resolve());
753 return true;
754 });
755
756 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
757 BasicType bt = (BasicType)i;
758 if (!is_reference_type(bt)) {
759 oop orig_mirror = Universe::java_mirror(bt);
760 oop m = _scratch_basic_type_mirrors[i].resolve();
761 assert(m != nullptr, "sanity");
762 bool success = archive_reachable_objects_from(1, _default_subgraph_info, m);
763 assert(success, "sanity");
764
765 log_trace(cds, heap, mirror)(
766 "Archived %s mirror object from " PTR_FORMAT,
767 type2name(bt), p2i(m));
768
769 Universe::set_archived_basic_type_mirror_index(bt, append_root(m));
770 }
771 }
772
773 GrowableArray<Klass*>* klasses = ArchiveBuilder::current()->klasses();
774 assert(klasses != nullptr, "sanity");
775
776 for (int i = 0; i < klasses->length(); i++) {
777 Klass* orig_k = klasses->at(i);
778 oop orig_mirror = orig_k->java_mirror();
779 oop m = scratch_java_mirror(orig_k);
780 if (m != nullptr) {
781 copy_aot_initialized_mirror(orig_k, orig_mirror, m);
782 if (CDSConfig::is_dumping_reflection_data() && java_lang_Class::has_reflection_data(orig_mirror)) {
783 oop reflection_data = java_lang_Class::reflection_data(orig_mirror);
784 bool success = archive_reachable_objects_from(1, _default_subgraph_info, reflection_data);
785 guarantee(success, "");
786 java_lang_Class::set_reflection_data(m, reflection_data);
787 }
788 }
789 }
790
791 for (int i = 0; i < klasses->length(); i++) {
792 Klass* orig_k = klasses->at(i);
793 oop orig_mirror = orig_k->java_mirror();
794 oop m = scratch_java_mirror(orig_k);
795 if (m != nullptr) {
796 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(orig_k);
797 bool success = archive_reachable_objects_from(1, _default_subgraph_info, m);
798 guarantee(success, "scratch mirrors must point to only archivable objects");
799 buffered_k->set_archived_java_mirror(append_root(m));
800 ResourceMark rm;
801 log_trace(cds, heap, mirror)(
802 "Archived %s mirror object from " PTR_FORMAT,
803 buffered_k->external_name(), p2i(m));
804
805 // archive the resolved_referenes array
806 if (buffered_k->is_instance_klass()) {
807 InstanceKlass* ik = InstanceKlass::cast(buffered_k);
808 oop rr = ik->constants()->prepare_resolved_references_for_archiving();
809 if (rr != nullptr && !ArchiveHeapWriter::is_too_large_to_archive(rr)) {
810 bool success = HeapShared::archive_reachable_objects_from(1, _default_subgraph_info, rr);
811 assert(success, "must be");
812 int root_index = append_root(rr);
813 ik->constants()->cache()->set_archived_references(root_index);
814 }
815 }
816 }
817 }
818 }
819
820 void HeapShared::archive_strings() {
821 oop shared_strings_array = StringTable::init_shared_table(_dumped_interned_strings);
822 bool success = archive_reachable_objects_from(1, _default_subgraph_info, shared_strings_array);
823 // We must succeed because:
824 // - _dumped_interned_strings do not contain any large strings.
825 // - StringTable::init_shared_table() doesn't create any large arrays.
826 assert(success, "shared strings array must not point to arrays or strings that are too large to archive");
827 StringTable::set_shared_strings_array_index(append_root(shared_strings_array));
828 }
829
830 int HeapShared::archive_exception_instance(oop exception) {
831 bool success = archive_reachable_objects_from(1, _default_subgraph_info, exception);
832 assert(success, "sanity");
833 return append_root(exception);
834 }
835
836 void HeapShared::mark_native_pointers(oop orig_obj) {
837 if (java_lang_Class::is_instance(orig_obj)) {
838 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::klass_offset());
839 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::array_klass_offset());
840 } else if (java_lang_invoke_ResolvedMethodName::is_instance(orig_obj)) {
841 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_invoke_ResolvedMethodName::vmtarget_offset());
842 }
843 }
844
845 void HeapShared::get_pointer_info(oop src_obj, bool& has_oop_pointers, bool& has_native_pointers) {
846 CachedOopInfo* info = archived_object_cache()->get(src_obj);
847 assert(info != nullptr, "must be");
848 has_oop_pointers = info->has_oop_pointers();
849 has_native_pointers = info->has_native_pointers();
850 }
851
852 void HeapShared::set_has_native_pointers(oop src_obj) {
853 CachedOopInfo* info = archived_object_cache()->get(src_obj);
854 assert(info != nullptr, "must be");
855 info->set_has_native_pointers();
856 }
857
858 void HeapShared::start_finding_archivable_hidden_classes() {
859 NoSafepointVerifier nsv;
860
861 init_seen_objects_table();
862
863 find_archivable_hidden_classes_helper(archive_subgraph_entry_fields);
864 if (CDSConfig::is_dumping_full_module_graph()) {
865 find_archivable_hidden_classes_helper(fmg_archive_subgraph_entry_fields);
866 }
867 }
868
869 void HeapShared::end_finding_archivable_hidden_classes() {
870 NoSafepointVerifier nsv;
871
872 delete_seen_objects_table();
873 }
874
875 void HeapShared::find_archivable_hidden_classes_helper(ArchivableStaticFieldInfo fields[]) {
876 if (!CDSConfig::is_dumping_heap()) {
877 return;
878 }
879 for (int i = 0; fields[i].valid(); ) {
880 ArchivableStaticFieldInfo* info = &fields[i];
881 const char* klass_name = info->klass_name;
882 for (; fields[i].valid(); i++) {
883 ArchivableStaticFieldInfo* f = &fields[i];
884 if (f->klass_name != klass_name) {
885 break;
886 }
887
888 InstanceKlass* k = f->klass;
889 oop m = k->java_mirror();
890 oop o = m->obj_field(f->offset);
891 if (o != nullptr) {
892 find_archivable_hidden_classes_in_object(o);
893 }
894 }
895 }
896 }
897
898 class HeapShared::FindHiddenClassesOopClosure: public BasicOopIterateClosure {
899 GrowableArray<oop> _stack;
900 template <class T> void do_oop_work(T *p) {
901 // Recurse on a GrowableArray to avoid overflowing the C stack.
902 oop o = RawAccess<>::oop_load(p);
903 if (o != nullptr) {
904 _stack.append(o);
905 }
906 }
907
908 public:
909
910 void do_oop(narrowOop *p) { FindHiddenClassesOopClosure::do_oop_work(p); }
911 void do_oop( oop *p) { FindHiddenClassesOopClosure::do_oop_work(p); }
912
913 FindHiddenClassesOopClosure(oop o) {
914 _stack.append(o);
915 }
916 oop pop() {
917 if (_stack.length() == 0) {
918 return nullptr;
919 } else {
920 return _stack.pop();
921 }
922 }
923 };
924
925 void HeapShared::find_archivable_hidden_classes_in_object(oop root) {
926 ResourceMark rm;
927 FindHiddenClassesOopClosure c(root);
928 oop o;
929 while ((o = c.pop()) != nullptr) {
930 if (!has_been_seen_during_subgraph_recording(o)) {
931 set_has_been_seen_during_subgraph_recording(o);
932
933 if (java_lang_Class::is_instance(o)) {
934 Klass* k = java_lang_Class::as_Klass(o);
935 if (k != nullptr && k->is_instance_klass()) {
936 SystemDictionaryShared::mark_required_class(InstanceKlass::cast(k));
937 }
938 } else if (java_lang_invoke_ResolvedMethodName::is_instance(o)) {
939 Method* m = java_lang_invoke_ResolvedMethodName::vmtarget(o);
940 if (m != nullptr && m->method_holder() != nullptr) {
941 SystemDictionaryShared::mark_required_class(m->method_holder());
942 }
943 }
944
945 o->oop_iterate(&c);
946 }
947 }
948 }
949
950 void HeapShared::archive_objects(ArchiveHeapInfo *heap_info) {
951 {
952 NoSafepointVerifier nsv;
953
954 _default_subgraph_info = init_subgraph_info(vmClasses::Object_klass(), false);
955 _trace = new GrowableArrayCHeap<oop, mtClassShared>(250);
956 _context = new GrowableArrayCHeap<const char*, mtClassShared>(250);
957
958 // Cache for recording where the archived objects are copied to
959 create_archived_object_cache();
960
961 if (UseCompressedOops || UseG1GC) {
962 log_info(cds)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]",
963 UseCompressedOops ? p2i(CompressedOops::begin()) :
964 p2i((address)G1CollectedHeap::heap()->reserved().start()),
965 UseCompressedOops ? p2i(CompressedOops::end()) :
966 p2i((address)G1CollectedHeap::heap()->reserved().end()));
967 }
968 copy_objects();
969
970 if (!SkipArchiveHeapVerification) {
971 CDSHeapVerifier::verify();
972 }
973 check_default_subgraph_classes();
974 }
975
976 GrowableArrayCHeap<oop, mtClassShared>* roots = new GrowableArrayCHeap<oop, mtClassShared>(_pending_roots->length());
977 for (int i = 0; i < _pending_roots->length(); i++) {
978 roots->append(_pending_roots->at(i).resolve());
979 }
980 ArchiveHeapWriter::write(roots, heap_info);
981 }
982
983 void HeapShared::copy_interned_strings() {
984 init_seen_objects_table();
985
986 auto copier = [&] (oop s, bool value_ignored) {
987 assert(s != nullptr, "sanity");
988 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(s), "large strings must have been filtered");
989 bool success = archive_reachable_objects_from(1, _default_subgraph_info, s);
990 assert(success, "must be");
991 // Prevent string deduplication from changing the value field to
992 // something not in the archive.
993 java_lang_String::set_deduplication_forbidden(s);
994 };
995 _dumped_interned_strings->iterate_all(copier);
996
997 delete_seen_objects_table();
998 }
999
1000 void HeapShared::copy_special_objects() {
1001 // Archive special objects that do not belong to any subgraphs
1002 init_seen_objects_table();
1003 archive_java_mirrors();
1004 archive_strings();
1005 Universe::archive_exception_instances();
1006 delete_seen_objects_table();
1007 }
1008
1009 void HeapShared::copy_objects() {
1010 assert(HeapShared::can_write(), "must be");
1011
1012 copy_interned_strings();
1013 copy_special_objects();
1014
1015 archive_object_subgraphs(archive_subgraph_entry_fields,
1016 false /* is_full_module_graph */);
1017
1018 if (CDSConfig::is_dumping_full_module_graph()) {
1019 archive_object_subgraphs(fmg_archive_subgraph_entry_fields,
1020 true /* is_full_module_graph */);
1021 Modules::verify_archived_modules();
1022 }
1023 }
1024
1025 //
1026 // Subgraph archiving support
1027 //
1028 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = nullptr;
1029 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table;
1030
1031 // Get the subgraph_info for Klass k. A new subgraph_info is created if
1032 // there is no existing one for k. The subgraph_info records the "buffered"
1033 // address of the class.
1034 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) {
1035 assert(CDSConfig::is_dumping_heap(), "dump time only");
1036 bool created;
1037 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(k);
1038 KlassSubGraphInfo* info =
1039 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(buffered_k, is_full_module_graph),
1040 &created);
1041 assert(created, "must not initialize twice");
1042 return info;
1043 }
1044
1045 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {
1046 assert(CDSConfig::is_dumping_heap(), "dump time only");
1047 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k);
1048 assert(info != nullptr, "must have been initialized");
1049 return info;
1050 }
1051
1052 // Add an entry field to the current KlassSubGraphInfo.
1053 void KlassSubGraphInfo::add_subgraph_entry_field(int static_field_offset, oop v) {
1054 assert(CDSConfig::is_dumping_heap(), "dump time only");
1055 if (_subgraph_entry_fields == nullptr) {
1056 _subgraph_entry_fields =
1057 new (mtClass) GrowableArray<int>(10, mtClass);
1058 }
1059 _subgraph_entry_fields->append(static_field_offset);
1060 _subgraph_entry_fields->append(HeapShared::append_root(v));
1061 }
1062
1063 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.
1064 // Only objects of boot classes can be included in sub-graph.
1065 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) {
1066 assert(CDSConfig::is_dumping_heap(), "dump time only");
1067 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(orig_k);
1068
1069 if (_subgraph_object_klasses == nullptr) {
1070 _subgraph_object_klasses =
1071 new (mtClass) GrowableArray<Klass*>(50, mtClass);
1072 }
1073
1074 assert(ArchiveBuilder::current()->is_in_buffer_space(buffered_k), "must be a shared class");
1075
1076 if (_k == buffered_k) {
1077 // Don't add the Klass containing the sub-graph to it's own klass
1078 // initialization list.
1079 return;
1080 }
1081
1082 if (buffered_k->is_instance_klass()) {
1083 if (CDSConfig::is_dumping_invokedynamic()) {
1084 assert(InstanceKlass::cast(buffered_k)->is_shared_boot_class() ||
1085 HeapShared::is_lambda_proxy_klass(InstanceKlass::cast(buffered_k)),
1086 "we can archive only instances of boot classes or lambda proxy classes");
1087 } else {
1088 assert(InstanceKlass::cast(buffered_k)->is_shared_boot_class(),
1089 "must be boot class");
1090 }
1091 // vmClasses::xxx_klass() are not updated, need to check
1092 // the original Klass*
1093 if (orig_k == vmClasses::String_klass() ||
1094 orig_k == vmClasses::Object_klass()) {
1095 // Initialized early during VM initialization. No need to be added
1096 // to the sub-graph object class list.
1097 return;
1098 }
1099 check_allowed_klass(InstanceKlass::cast(orig_k));
1100 } else if (buffered_k->is_objArray_klass()) {
1101 Klass* abk = ObjArrayKlass::cast(buffered_k)->bottom_klass();
1102 if (abk->is_instance_klass()) {
1103 assert(InstanceKlass::cast(abk)->is_shared_boot_class(),
1104 "must be boot class");
1105 check_allowed_klass(InstanceKlass::cast(ObjArrayKlass::cast(orig_k)->bottom_klass()));
1106 }
1107 if (buffered_k == Universe::objectArrayKlass()) {
1108 // Initialized early during Universe::genesis. No need to be added
1109 // to the list.
1110 return;
1111 }
1112 } else {
1113 assert(buffered_k->is_typeArray_klass(), "must be");
1114 // Primitive type arrays are created early during Universe::genesis.
1115 return;
1116 }
1117
1118 if (log_is_enabled(Debug, cds, heap)) {
1119 if (!_subgraph_object_klasses->contains(buffered_k)) {
1120 ResourceMark rm;
1121 log_debug(cds, heap)("Adding klass %s", orig_k->external_name());
1122 }
1123 }
1124
1125 _subgraph_object_klasses->append_if_missing(buffered_k);
1126 _has_non_early_klasses |= is_non_early_klass(orig_k);
1127 }
1128
1129 void KlassSubGraphInfo::check_allowed_klass(InstanceKlass* ik) {
1130 if (CDSConfig::is_dumping_invokedynamic()) {
1131 // FIXME -- this allows LambdaProxy classes
1132 return;
1133 }
1134 if (ik->module()->name() == vmSymbols::java_base()) {
1135 assert(ik->package() != nullptr, "classes in java.base cannot be in unnamed package");
1136 return;
1137 }
1138
1139 #ifndef PRODUCT
1140 if (!ik->module()->is_named() && ik->package() == nullptr) {
1141 // This class is loaded by ArchiveHeapTestClass
1142 return;
1143 }
1144 const char* extra_msg = ", or in an unnamed package of an unnamed module";
1145 #else
1146 const char* extra_msg = "";
1147 #endif
1148
1149 ResourceMark rm;
1150 log_error(cds, heap)("Class %s not allowed in archive heap. Must be in java.base%s",
1151 ik->external_name(), extra_msg);
1152 MetaspaceShared::unrecoverable_writing_error();
1153 }
1154
1155 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) {
1156 if (k->is_objArray_klass()) {
1157 k = ObjArrayKlass::cast(k)->bottom_klass();
1158 }
1159 if (k->is_instance_klass()) {
1160 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) {
1161 ResourceMark rm;
1162 log_info(cds, heap)("non-early: %s", k->external_name());
1163 return true;
1164 } else {
1165 return false;
1166 }
1167 } else {
1168 return false;
1169 }
1170 }
1171
1172 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.
1173 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {
1174 _k = info->klass();
1175 _entry_field_records = nullptr;
1176 _subgraph_object_klasses = nullptr;
1177 _is_full_module_graph = info->is_full_module_graph();
1178
1179 if (_is_full_module_graph) {
1180 // Consider all classes referenced by the full module graph as early -- we will be
1181 // allocating objects of these classes during JVMTI early phase, so they cannot
1182 // be processed by (non-early) JVMTI ClassFileLoadHook
1183 _has_non_early_klasses = false;
1184 } else {
1185 _has_non_early_klasses = info->has_non_early_klasses();
1186 }
1187
1188 if (_has_non_early_klasses) {
1189 ResourceMark rm;
1190 log_info(cds, heap)(
1191 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled",
1192 _k->external_name());
1193 }
1194
1195 // populate the entry fields
1196 GrowableArray<int>* entry_fields = info->subgraph_entry_fields();
1197 if (entry_fields != nullptr) {
1198 int num_entry_fields = entry_fields->length();
1199 assert(num_entry_fields % 2 == 0, "sanity");
1200 _entry_field_records =
1201 ArchiveBuilder::new_ro_array<int>(num_entry_fields);
1202 for (int i = 0 ; i < num_entry_fields; i++) {
1203 _entry_field_records->at_put(i, entry_fields->at(i));
1204 }
1205 }
1206
1207 // the Klasses of the objects in the sub-graphs
1208 GrowableArray<Klass*>* subgraph_object_klasses = info->subgraph_object_klasses();
1209 if (subgraph_object_klasses != nullptr) {
1210 int num_subgraphs_klasses = subgraph_object_klasses->length();
1211 _subgraph_object_klasses =
1212 ArchiveBuilder::new_ro_array<Klass*>(num_subgraphs_klasses);
1213 for (int i = 0; i < num_subgraphs_klasses; i++) {
1214 Klass* subgraph_k = subgraph_object_klasses->at(i);
1215 if (log_is_enabled(Info, cds, heap)) {
1216 ResourceMark rm;
1217 log_info(cds, heap)(
1218 "Archived object klass %s (%2d) => %s",
1219 _k->external_name(), i, subgraph_k->external_name());
1220 }
1221 _subgraph_object_klasses->at_put(i, subgraph_k);
1222 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(i));
1223 }
1224 }
1225
1226 ArchivePtrMarker::mark_pointer(&_k);
1227 ArchivePtrMarker::mark_pointer(&_entry_field_records);
1228 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses);
1229 }
1230
1231 class HeapShared::CopyKlassSubGraphInfoToArchive : StackObj {
1232 CompactHashtableWriter* _writer;
1233 public:
1234 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}
1235
1236 bool do_entry(Klass* klass, KlassSubGraphInfo& info) {
1237 if (info.subgraph_object_klasses() != nullptr || info.subgraph_entry_fields() != nullptr) {
1238 ArchivedKlassSubGraphInfoRecord* record = HeapShared::archive_subgraph_info(&info);
1239 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(klass);
1240 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)buffered_k);
1241 u4 delta = ArchiveBuilder::current()->any_to_offset_u4(record);
1242 _writer->add(hash, delta);
1243 }
1244 return true; // keep on iterating
1245 }
1246 };
1247
1248 ArchivedKlassSubGraphInfoRecord* HeapShared::archive_subgraph_info(KlassSubGraphInfo* info) {
1249 ArchivedKlassSubGraphInfoRecord* record =
1250 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));
1251 record->init(info);
1252 if (info == _default_subgraph_info) {
1253 _runtime_default_subgraph_info = record;
1254 }
1255 return record;
1256 }
1257
1258 // Build the records of archived subgraph infos, which include:
1259 // - Entry points to all subgraphs from the containing class mirror. The entry
1260 // points are static fields in the mirror. For each entry point, the field
1261 // offset, and value are recorded in the sub-graph
1262 // info. The value is stored back to the corresponding field at runtime.
1263 // - A list of klasses that need to be loaded/initialized before archived
1264 // java object sub-graph can be accessed at runtime.
1265 void HeapShared::write_subgraph_info_table() {
1266 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.
1267 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;
1268 CompactHashtableStats stats;
1269
1270 _run_time_subgraph_info_table.reset();
1271
1272 CompactHashtableWriter writer(d_table->_count, &stats);
1273 CopyKlassSubGraphInfoToArchive copy(&writer);
1274 d_table->iterate(©);
1275 writer.dump(&_run_time_subgraph_info_table, "subgraphs");
1276
1277 #ifndef PRODUCT
1278 if (ArchiveHeapTestClass != nullptr) {
1279 size_t len = strlen(ArchiveHeapTestClass) + 1;
1280 Array<char>* array = ArchiveBuilder::new_ro_array<char>((int)len);
1281 strncpy(array->adr_at(0), ArchiveHeapTestClass, len);
1282 _archived_ArchiveHeapTestClass = array;
1283 }
1284 #endif
1285 if (log_is_enabled(Info, cds, heap)) {
1286 print_stats();
1287 }
1288 }
1289
1290 void HeapShared::add_root_segment(objArrayOop segment_oop) {
1291 assert(segment_oop != nullptr, "must be");
1292 assert(ArchiveHeapLoader::is_in_use(), "must be");
1293 if (_root_segments == nullptr) {
1294 _root_segments = new GrowableArrayCHeap<OopHandle, mtClassShared>(10);
1295 }
1296 _root_segments->push(OopHandle(Universe::vm_global(), segment_oop));
1297 }
1298
1299 void HeapShared::init_root_segment_sizes(int max_size_elems) {
1300 _root_segment_max_size_elems = max_size_elems;
1301 }
1302
1303 void HeapShared::serialize_tables(SerializeClosure* soc) {
1304
1305 #ifndef PRODUCT
1306 soc->do_ptr(&_archived_ArchiveHeapTestClass);
1307 if (soc->reading() && _archived_ArchiveHeapTestClass != nullptr) {
1308 _test_class_name = _archived_ArchiveHeapTestClass->adr_at(0);
1309 setup_test_class(_test_class_name);
1310 }
1311 #endif
1312
1313 _run_time_subgraph_info_table.serialize_header(soc);
1314 soc->do_ptr(&_runtime_default_subgraph_info);
1315 }
1316
1317 static void verify_the_heap(Klass* k, const char* which) {
1318 if (VerifyArchivedFields > 0) {
1319 ResourceMark rm;
1320 log_info(cds, heap)("Verify heap %s initializing static field(s) in %s",
1321 which, k->external_name());
1322
1323 VM_Verify verify_op;
1324 VMThread::execute(&verify_op);
1325
1326 if (VerifyArchivedFields > 1 && is_init_completed()) {
1327 // At this time, the oop->klass() of some archived objects in the heap may not
1328 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should
1329 // have enough information (object size, oop maps, etc) so that a GC can be safely
1330 // performed.
1331 //
1332 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage
1333 // to check for GC safety.
1334 log_info(cds, heap)("Trigger GC %s initializing static field(s) in %s",
1335 which, k->external_name());
1336 FlagSetting fs1(VerifyBeforeGC, true);
1337 FlagSetting fs2(VerifyDuringGC, true);
1338 FlagSetting fs3(VerifyAfterGC, true);
1339 Universe::heap()->collect(GCCause::_java_lang_system_gc);
1340 }
1341 }
1342 }
1343
1344 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots()
1345 // have a valid klass. I.e., oopDesc::klass() must have already been resolved.
1346 //
1347 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI
1348 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In
1349 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots.
1350 void HeapShared::resolve_classes(JavaThread* current) {
1351 assert(CDSConfig::is_using_archive(), "runtime only!");
1352 if (!ArchiveHeapLoader::is_in_use()) {
1353 return; // nothing to do
1354 }
1355
1356 if (!CDSConfig::is_using_aot_linked_classes()) {
1357 assert( _runtime_default_subgraph_info != nullptr, "must be");
1358 Array<Klass*>* klasses = _runtime_default_subgraph_info->subgraph_object_klasses();
1359 if (klasses != nullptr) {
1360 for (int i = 0; i < klasses->length(); i++) {
1361 Klass* k = klasses->at(i);
1362 ExceptionMark em(current); // no exception can happen here
1363 resolve_or_init(k, /*do_init*/false, current);
1364 }
1365 }
1366 }
1367
1368 resolve_classes_for_subgraphs(current, archive_subgraph_entry_fields);
1369 resolve_classes_for_subgraphs(current, fmg_archive_subgraph_entry_fields);
1370 }
1371
1372 void HeapShared::resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]) {
1373 for (int i = 0; fields[i].valid(); i++) {
1374 ArchivableStaticFieldInfo* info = &fields[i];
1375 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
1376 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name);
1377 assert(k != nullptr && k->is_shared_boot_class(), "sanity");
1378 resolve_classes_for_subgraph_of(current, k);
1379 }
1380 }
1381
1382 void HeapShared::resolve_classes_for_subgraph_of(JavaThread* current, Klass* k) {
1383 JavaThread* THREAD = current;
1384 ExceptionMark em(THREAD);
1385 const ArchivedKlassSubGraphInfoRecord* record =
1386 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
1387 if (HAS_PENDING_EXCEPTION) {
1388 CLEAR_PENDING_EXCEPTION;
1389 }
1390 if (record == nullptr) {
1391 clear_archived_roots_of(k);
1392 }
1393 }
1394
1395 void HeapShared::initialize_java_lang_invoke(TRAPS) {
1396 if (CDSConfig::is_loading_invokedynamic() || CDSConfig::is_dumping_invokedynamic()) {
1397 resolve_or_init("java/lang/invoke/Invokers$Holder", true, CHECK);
1398 resolve_or_init("java/lang/invoke/MethodHandle", true, CHECK);
1399 resolve_or_init("java/lang/invoke/MethodHandleNatives", true, CHECK);
1400 resolve_or_init("java/lang/invoke/DirectMethodHandle$Holder", true, CHECK);
1401 resolve_or_init("java/lang/invoke/DelegatingMethodHandle$Holder", true, CHECK);
1402 resolve_or_init("java/lang/invoke/LambdaForm$Holder", true, CHECK);
1403 resolve_or_init("java/lang/invoke/BoundMethodHandle$Species_L", true, CHECK);
1404 }
1405 }
1406
1407 void HeapShared::initialize_default_subgraph_classes(Handle class_loader, TRAPS) {
1408 if (!ArchiveHeapLoader::is_in_use()) {
1409 return;
1410 }
1411
1412 assert( _runtime_default_subgraph_info != nullptr, "must be");
1413 Array<Klass*>* klasses = _runtime_default_subgraph_info->subgraph_object_klasses();
1414 if (klasses != nullptr) {
1415 for (int pass = 0; pass < 2; pass ++) {
1416 for (int i = 0; i < klasses->length(); i++) {
1417 Klass* k = klasses->at(i);
1418 if (k->class_loader_data() == nullptr) {
1419 // This class is not yet loaded. We will initialize it in a later phase.
1420 continue;
1421 }
1422 if (k->class_loader() == class_loader()) {
1423 if (pass == 0) {
1424 if (k->is_instance_klass()) {
1425 InstanceKlass::cast(k)->link_class(CHECK);
1426 }
1427 } else {
1428 resolve_or_init(k, /*do_init*/true, CHECK);
1429 }
1430 }
1431 }
1432 }
1433 }
1434 }
1435
1436 void HeapShared::initialize_from_archived_subgraph(JavaThread* current, Klass* k) {
1437 JavaThread* THREAD = current;
1438 if (!ArchiveHeapLoader::is_in_use()) {
1439 return; // nothing to do
1440 }
1441
1442 if (k->name()->equals("jdk/internal/module/ArchivedModuleGraph") &&
1443 !CDSConfig::is_using_optimized_module_handling() &&
1444 // archive was created with --module-path
1445 ClassLoaderExt::num_module_paths() > 0) {
1446 // ArchivedModuleGraph was created with a --module-path that's different than the runtime --module-path.
1447 // Thus, it might contain references to modules that do not exist at runtime. We cannot use it.
1448 log_info(cds, heap)("Skip initializing ArchivedModuleGraph subgraph: is_using_optimized_module_handling=%s num_module_paths=%d",
1449 BOOL_TO_STR(CDSConfig::is_using_optimized_module_handling()), ClassLoaderExt::num_module_paths());
1450 return;
1451 }
1452
1453 ExceptionMark em(THREAD);
1454 const ArchivedKlassSubGraphInfoRecord* record =
1455 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
1456
1457 if (HAS_PENDING_EXCEPTION) {
1458 CLEAR_PENDING_EXCEPTION;
1459 // None of the field value will be set if there was an exception when initializing the classes.
1460 // The java code will not see any of the archived objects in the
1461 // subgraphs referenced from k in this case.
1462 return;
1463 }
1464
1465 if (record != nullptr) {
1466 init_archived_fields_for(k, record);
1467 }
1468 }
1469
1470 const ArchivedKlassSubGraphInfoRecord*
1471 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) {
1472 assert(!CDSConfig::is_dumping_heap(), "Should not be called when dumping heap");
1473
1474 if (!k->is_shared()) {
1475 return nullptr;
1476 }
1477 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1478 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1479
1480 #ifndef PRODUCT
1481 if (_test_class_name != nullptr && k->name()->equals(_test_class_name) && record != nullptr) {
1482 _test_class = k;
1483 _test_class_record = record;
1484 }
1485 #endif
1486
1487 // Initialize from archived data. Currently this is done only
1488 // during VM initialization time. No lock is needed.
1489 if (record == nullptr) {
1490 if (log_is_enabled(Info, cds, heap)) {
1491 ResourceMark rm(THREAD);
1492 log_info(cds, heap)("subgraph %s is not recorded",
1493 k->external_name());
1494 }
1495 return nullptr;
1496 } else {
1497 if (record->is_full_module_graph() && !CDSConfig::is_using_full_module_graph()) {
1498 if (log_is_enabled(Info, cds, heap)) {
1499 ResourceMark rm(THREAD);
1500 log_info(cds, heap)("subgraph %s cannot be used because full module graph is disabled",
1501 k->external_name());
1502 }
1503 return nullptr;
1504 }
1505
1506 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) {
1507 if (log_is_enabled(Info, cds, heap)) {
1508 ResourceMark rm(THREAD);
1509 log_info(cds, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled",
1510 k->external_name());
1511 }
1512 return nullptr;
1513 }
1514
1515 if (log_is_enabled(Info, cds, heap)) {
1516 ResourceMark rm;
1517 log_info(cds, heap)("%s subgraph %s ", do_init ? "init" : "resolve", k->external_name());
1518 }
1519
1520 resolve_or_init(k, do_init, CHECK_NULL);
1521
1522 // Load/link/initialize the klasses of the objects in the subgraph.
1523 // nullptr class loader is used.
1524 Array<Klass*>* klasses = record->subgraph_object_klasses();
1525 if (klasses != nullptr) {
1526 for (int i = 0; i < klasses->length(); i++) {
1527 Klass* klass = klasses->at(i);
1528 if (!klass->is_shared()) {
1529 return nullptr;
1530 }
1531 resolve_or_init(klass, do_init, CHECK_NULL);
1532 }
1533 }
1534 }
1535
1536 return record;
1537 }
1538
1539 void HeapShared::resolve_or_init(const char* klass_name, bool do_init, TRAPS) {
1540 TempNewSymbol klass_name_sym = SymbolTable::new_symbol(klass_name);
1541 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name_sym);
1542 if (k == nullptr) {
1543 return;
1544 }
1545 assert(k->is_shared_boot_class(), "sanity");
1546 resolve_or_init(k, false, CHECK);
1547 if (do_init) {
1548 resolve_or_init(k, true, CHECK);
1549 }
1550 }
1551
1552 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) {
1553 if (!do_init) {
1554 if (k->class_loader_data() == nullptr) {
1555 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK);
1556 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook");
1557 }
1558 } else {
1559 assert(k->class_loader_data() != nullptr, "must have been resolved by HeapShared::resolve_classes");
1560 if (k->is_instance_klass()) {
1561 InstanceKlass* ik = InstanceKlass::cast(k);
1562 ik->initialize(CHECK);
1563 } else if (k->is_objArray_klass()) {
1564 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
1565 oak->initialize(CHECK);
1566 }
1567 }
1568 }
1569
1570 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) {
1571 verify_the_heap(k, "before");
1572
1573 // Load the subgraph entry fields from the record and store them back to
1574 // the corresponding fields within the mirror.
1575 oop m = k->java_mirror();
1576 Array<int>* entry_field_records = record->entry_field_records();
1577 if (entry_field_records != nullptr) {
1578 int efr_len = entry_field_records->length();
1579 assert(efr_len % 2 == 0, "sanity");
1580 for (int i = 0; i < efr_len; i += 2) {
1581 int field_offset = entry_field_records->at(i);
1582 int root_index = entry_field_records->at(i+1);
1583 oop v = get_root(root_index, /*clear=*/true);
1584 m->obj_field_put(field_offset, v);
1585 log_debug(cds, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v));
1586 }
1587
1588 // Done. Java code can see the archived sub-graphs referenced from k's
1589 // mirror after this point.
1590 if (log_is_enabled(Info, cds, heap)) {
1591 ResourceMark rm;
1592 log_info(cds, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s",
1593 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : "");
1594 }
1595 }
1596
1597 verify_the_heap(k, "after ");
1598 }
1599
1600 void HeapShared::clear_archived_roots_of(Klass* k) {
1601 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1602 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1603 if (record != nullptr) {
1604 Array<int>* entry_field_records = record->entry_field_records();
1605 if (entry_field_records != nullptr) {
1606 int efr_len = entry_field_records->length();
1607 assert(efr_len % 2 == 0, "sanity");
1608 for (int i = 0; i < efr_len; i += 2) {
1609 int root_index = entry_field_records->at(i+1);
1610 clear_root(root_index);
1611 }
1612 }
1613 }
1614 }
1615
1616 class WalkOopAndArchiveClosure: public BasicOopIterateClosure {
1617 int _level;
1618 bool _record_klasses_only;
1619 KlassSubGraphInfo* _subgraph_info;
1620 oop _referencing_obj;
1621
1622 // The following are for maintaining a stack for determining
1623 // CachedOopInfo::_referrer
1624 static WalkOopAndArchiveClosure* _current;
1625 WalkOopAndArchiveClosure* _last;
1626 public:
1627 WalkOopAndArchiveClosure(int level,
1628 bool record_klasses_only,
1629 KlassSubGraphInfo* subgraph_info,
1630 oop orig) :
1631 _level(level),
1632 _record_klasses_only(record_klasses_only),
1633 _subgraph_info(subgraph_info),
1634 _referencing_obj(orig) {
1635 _last = _current;
1636 _current = this;
1637 }
1638 ~WalkOopAndArchiveClosure() {
1639 _current = _last;
1640 }
1641 void do_oop(narrowOop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
1642 void do_oop( oop *p) { WalkOopAndArchiveClosure::do_oop_work(p); }
1643
1644 protected:
1645 template <class T> void do_oop_work(T *p) {
1646 oop obj = RawAccess<>::oop_load(p);
1647 if (!CompressedOops::is_null(obj)) {
1648 size_t field_delta = pointer_delta(p, _referencing_obj, sizeof(char));
1649
1650 if (!_record_klasses_only && log_is_enabled(Debug, cds, heap)) {
1651 ResourceMark rm;
1652 log_debug(cds, heap)("(%d) %s[" SIZE_FORMAT "] ==> " PTR_FORMAT " size " SIZE_FORMAT " %s", _level,
1653 _referencing_obj->klass()->external_name(), field_delta,
1654 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());
1655 if (log_is_enabled(Trace, cds, heap)) {
1656 LogTarget(Trace, cds, heap) log;
1657 LogStream out(log);
1658 obj->print_on(&out);
1659 }
1660 }
1661
1662 bool success = HeapShared::archive_reachable_objects_from(
1663 _level + 1, _subgraph_info, obj);
1664 assert(success, "VM should have exited with unarchivable objects for _level > 1");
1665 }
1666 }
1667
1668 public:
1669 static WalkOopAndArchiveClosure* current() { return _current; }
1670 oop referencing_obj() { return _referencing_obj; }
1671 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; }
1672 };
1673
1674 WalkOopAndArchiveClosure* WalkOopAndArchiveClosure::_current = nullptr;
1675
1676 // Checks if an oop has any non-null oop fields
1677 class PointsToOopsChecker : public BasicOopIterateClosure {
1678 bool _result;
1679
1680 template <class T> void check(T *p) {
1681 _result |= (HeapAccess<>::oop_load(p) != nullptr);
1682 }
1683
1684 public:
1685 PointsToOopsChecker() : _result(false) {}
1686 void do_oop(narrowOop *p) { check(p); }
1687 void do_oop( oop *p) { check(p); }
1688 bool result() { return _result; }
1689 };
1690
1691 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info(oop obj) {
1692 WalkOopAndArchiveClosure* walker = WalkOopAndArchiveClosure::current();
1693 oop referrer = (walker == nullptr) ? nullptr : walker->referencing_obj();
1694 PointsToOopsChecker points_to_oops_checker;
1695 obj->oop_iterate(&points_to_oops_checker);
1696 return CachedOopInfo(referrer, points_to_oops_checker.result());
1697 }
1698
1699 // We currently allow only the box classes, as well as j.l.Object, which are
1700 // initialized very early by HeapShared::init_box_classes().
1701 bool HeapShared::can_mirror_be_used_in_subgraph(oop orig_java_mirror) {
1702 return java_lang_Class::is_primitive(orig_java_mirror)
1703 || orig_java_mirror == vmClasses::Boolean_klass()->java_mirror()
1704 || orig_java_mirror == vmClasses::Character_klass()->java_mirror()
1705 || orig_java_mirror == vmClasses::Float_klass()->java_mirror()
1706 || orig_java_mirror == vmClasses::Double_klass()->java_mirror()
1707 || orig_java_mirror == vmClasses::Byte_klass()->java_mirror()
1708 || orig_java_mirror == vmClasses::Short_klass()->java_mirror()
1709 || orig_java_mirror == vmClasses::Integer_klass()->java_mirror()
1710 || orig_java_mirror == vmClasses::Long_klass()->java_mirror()
1711 || orig_java_mirror == vmClasses::Void_klass()->java_mirror()
1712 || orig_java_mirror == vmClasses::Object_klass()->java_mirror();
1713 }
1714
1715 void HeapShared::init_box_classes(TRAPS) {
1716 if (ArchiveHeapLoader::is_in_use()) {
1717 vmClasses::Boolean_klass()->initialize(CHECK);
1718 vmClasses::Character_klass()->initialize(CHECK);
1719 vmClasses::Float_klass()->initialize(CHECK);
1720 vmClasses::Double_klass()->initialize(CHECK);
1721 vmClasses::Byte_klass()->initialize(CHECK);
1722 vmClasses::Short_klass()->initialize(CHECK);
1723 vmClasses::Integer_klass()->initialize(CHECK);
1724 vmClasses::Long_klass()->initialize(CHECK);
1725 vmClasses::Void_klass()->initialize(CHECK);
1726 }
1727 }
1728
1729 void HeapShared::exit_on_error() {
1730 if (_context != nullptr) {
1731 ResourceMark rm;
1732 LogStream ls(Log(cds, heap)::error());
1733 ls.print_cr("Context");
1734 for (int i = 0; i < _context->length(); i++) {
1735 const char* s = _context->at(i);
1736 ls.print_cr("- %s", s);
1737 }
1738 }
1739 if (_trace != nullptr) {
1740 ResourceMark rm;
1741 LogStream ls(Log(cds, heap)::error());
1742 ls.print_cr("Reference trace");
1743 for (int i = 0; i < _trace->length(); i++) {
1744 oop orig_obj = _trace->at(i);
1745 ls.print_cr("[%d] ========================================", i);
1746 orig_obj->print_on(&ls);
1747 ls.cr();
1748 }
1749 }
1750 MetaspaceShared::unrecoverable_writing_error();
1751 }
1752
1753 void HeapShared::debug_trace() {
1754 WalkOopAndArchiveClosure* walker = WalkOopAndArchiveClosure::current();
1755 if (walker != nullptr) {
1756 LogStream ls(Log(cds, heap)::error());
1757 CDSHeapVerifier::trace_to_root(&ls, walker->referencing_obj());
1758 }
1759 }
1760
1761 // (1) If orig_obj has not been archived yet, archive it.
1762 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called),
1763 // trace all objects that are reachable from it, and make sure these objects are archived.
1764 // (3) Record the klasses of all orig_obj and all reachable objects.
1765 bool HeapShared::archive_reachable_objects_from(int level,
1766 KlassSubGraphInfo* subgraph_info,
1767 oop orig_obj) {
1768 ArchivingObjectMark mark(orig_obj);
1769 assert(orig_obj != nullptr, "must be");
1770
1771 if (!JavaClasses::is_supported_for_archiving(orig_obj)) {
1772 // This object has injected fields that cannot be supported easily, so we disallow them for now.
1773 // If you get an error here, you probably made a change in the JDK library that has added
1774 // these objects that are referenced (directly or indirectly) by static fields.
1775 ResourceMark rm;
1776 log_error(cds, heap)("Cannot archive object " PTR_FORMAT " of class %s", p2i(orig_obj), orig_obj->klass()->external_name());
1777 debug_trace();
1778 exit_on_error();
1779 }
1780
1781 if (log_is_enabled(Debug, cds, heap) && java_lang_Class::is_instance(orig_obj)) {
1782 ResourceMark rm;
1783 LogTarget(Debug, cds, heap) log;
1784 LogStream out(log);
1785 out.print("Found java mirror " PTR_FORMAT " ", p2i(orig_obj));
1786 Klass* k = java_lang_Class::as_Klass(orig_obj);
1787 if (k != nullptr) {
1788 out.print("%s", k->external_name());
1789 } else {
1790 out.print("primitive");
1791 }
1792 out.print_cr("; scratch mirror = " PTR_FORMAT,
1793 p2i(scratch_java_mirror(orig_obj)));
1794 }
1795
1796 if (java_lang_Class::is_instance(orig_obj)) {
1797 orig_obj = scratch_java_mirror(orig_obj);
1798 assert(orig_obj != nullptr, "must be archived");
1799 }
1800
1801 if (has_been_seen_during_subgraph_recording(orig_obj)) {
1802 // orig_obj has already been archived and traced. Nothing more to do.
1803 return true;
1804 } else {
1805 set_has_been_seen_during_subgraph_recording(orig_obj);
1806 }
1807
1808 bool already_archived = has_been_archived(orig_obj);
1809 bool record_klasses_only = already_archived;
1810 if (!already_archived) {
1811 ++_num_new_archived_objs;
1812 if (!archive_object(orig_obj)) {
1813 // Skip archiving the sub-graph referenced from the current entry field.
1814 ResourceMark rm;
1815 log_error(cds, heap)(
1816 "Cannot archive the sub-graph referenced from %s object ("
1817 PTR_FORMAT ") size " SIZE_FORMAT ", skipped.",
1818 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize);
1819 if (level == 1) {
1820 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1821 // as the Java code will take care of initializing this field dynamically.
1822 return false;
1823 } else {
1824 // We don't know how to handle an object that has been archived, but some of its reachable
1825 // objects cannot be archived. Bail out for now. We might need to fix this in the future if
1826 // we have a real use case.
1827 exit_on_error();
1828 }
1829 }
1830 }
1831
1832 Klass *orig_k = orig_obj->klass();
1833 subgraph_info->add_subgraph_object_klass(orig_k);
1834
1835 WalkOopAndArchiveClosure walker(level, record_klasses_only, subgraph_info, orig_obj);
1836 orig_obj->oop_iterate(&walker);
1837
1838 if (CDSConfig::is_initing_classes_at_dump_time()) {
1839 // The enum klasses are archived with preinitialized mirror.
1840 // See AOTClassInitializer::can_archive_initialized_mirror.
1841 } else {
1842 if (CDSEnumKlass::is_enum_obj(orig_obj)) {
1843 CDSEnumKlass::handle_enum_obj(level + 1, subgraph_info, orig_obj);
1844 }
1845 }
1846
1847 return true;
1848 }
1849
1850 //
1851 // Start from the given static field in a java mirror and archive the
1852 // complete sub-graph of java heap objects that are reached directly
1853 // or indirectly from the starting object by following references.
1854 // Sub-graph archiving restrictions (current):
1855 //
1856 // - All classes of objects in the archived sub-graph (including the
1857 // entry class) must be boot class only.
1858 // - No java.lang.Class instance (java mirror) can be included inside
1859 // an archived sub-graph. Mirror can only be the sub-graph entry object.
1860 //
1861 // The Java heap object sub-graph archiving process (see
1862 // WalkOopAndArchiveClosure):
1863 //
1864 // 1) Java object sub-graph archiving starts from a given static field
1865 // within a Class instance (java mirror). If the static field is a
1866 // reference field and points to a non-null java object, proceed to
1867 // the next step.
1868 //
1869 // 2) Archives the referenced java object. If an archived copy of the
1870 // current object already exists, updates the pointer in the archived
1871 // copy of the referencing object to point to the current archived object.
1872 // Otherwise, proceed to the next step.
1873 //
1874 // 3) Follows all references within the current java object and recursively
1875 // archive the sub-graph of objects starting from each reference.
1876 //
1877 // 4) Updates the pointer in the archived copy of referencing object to
1878 // point to the current archived object.
1879 //
1880 // 5) The Klass of the current java object is added to the list of Klasses
1881 // for loading and initializing before any object in the archived graph can
1882 // be accessed at runtime.
1883 //
1884 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k,
1885 const char* klass_name,
1886 int field_offset,
1887 const char* field_name) {
1888 assert(CDSConfig::is_dumping_heap(), "dump time only");
1889 assert(k->is_shared_boot_class(), "must be boot class");
1890
1891 oop m = k->java_mirror();
1892
1893 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
1894 oop f = m->obj_field(field_offset);
1895
1896 log_debug(cds, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f));
1897
1898 if (!CompressedOops::is_null(f)) {
1899 if (log_is_enabled(Trace, cds, heap)) {
1900 LogTarget(Trace, cds, heap) log;
1901 LogStream out(log);
1902 f->print_on(&out);
1903 }
1904
1905 bool success = archive_reachable_objects_from(1, subgraph_info, f);
1906 if (!success) {
1907 log_error(cds, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)",
1908 klass_name, field_name);
1909 } else {
1910 // Note: the field value is not preserved in the archived mirror.
1911 // Record the field as a new subGraph entry point. The recorded
1912 // information is restored from the archive at runtime.
1913 subgraph_info->add_subgraph_entry_field(field_offset, f);
1914 log_info(cds, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(f));
1915 }
1916 } else {
1917 // The field contains null, we still need to record the entry point,
1918 // so it can be restored at runtime.
1919 subgraph_info->add_subgraph_entry_field(field_offset, nullptr);
1920 }
1921 }
1922
1923 #ifndef PRODUCT
1924 class VerifySharedOopClosure: public BasicOopIterateClosure {
1925 public:
1926 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); }
1927 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); }
1928
1929 protected:
1930 template <class T> void do_oop_work(T *p) {
1931 oop obj = RawAccess<>::oop_load(p);
1932 if (!CompressedOops::is_null(obj)) {
1933 HeapShared::verify_reachable_objects_from(obj);
1934 }
1935 }
1936 };
1937
1938 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) {
1939 assert(CDSConfig::is_dumping_heap(), "dump time only");
1940 assert(k->is_shared_boot_class(), "must be boot class");
1941
1942 oop m = k->java_mirror();
1943 oop f = m->obj_field(field_offset);
1944 if (!CompressedOops::is_null(f)) {
1945 verify_subgraph_from(f);
1946 }
1947 }
1948
1949 void HeapShared::verify_subgraph_from(oop orig_obj) {
1950 if (!has_been_archived(orig_obj)) {
1951 // It's OK for the root of a subgraph to be not archived. See comments in
1952 // archive_reachable_objects_from().
1953 return;
1954 }
1955
1956 // Verify that all objects reachable from orig_obj are archived.
1957 init_seen_objects_table();
1958 verify_reachable_objects_from(orig_obj);
1959 delete_seen_objects_table();
1960 }
1961
1962 void HeapShared::verify_reachable_objects_from(oop obj) {
1963 _num_total_verifications ++;
1964 if (java_lang_Class::is_instance(obj)) {
1965 obj = scratch_java_mirror(obj);
1966 assert(obj != nullptr, "must be");
1967 }
1968 if (!has_been_seen_during_subgraph_recording(obj)) {
1969 set_has_been_seen_during_subgraph_recording(obj);
1970 assert(has_been_archived(obj), "must be");
1971 VerifySharedOopClosure walker;
1972 obj->oop_iterate(&walker);
1973 }
1974 }
1975 #endif
1976
1977 // The "default subgraph" contains special objects (see heapShared.hpp) that
1978 // can be accessed before we load any Java classes (including java/lang/Class).
1979 // Make sure that these are only instances of the very few specific types
1980 // that we can handle.
1981 void HeapShared::check_default_subgraph_classes() {
1982 if (CDSConfig::is_initing_classes_at_dump_time()) {
1983 return;
1984 }
1985
1986 GrowableArray<Klass*>* klasses = _default_subgraph_info->subgraph_object_klasses();
1987 int num = klasses->length();
1988 for (int i = 0; i < num; i++) {
1989 Klass* subgraph_k = klasses->at(i);
1990 Symbol* name = ArchiveBuilder::current()->get_source_addr(subgraph_k->name());
1991 if (subgraph_k->is_instance_klass() &&
1992 name != vmSymbols::java_lang_Class() &&
1993 name != vmSymbols::java_lang_String() &&
1994 name != vmSymbols::java_lang_ArithmeticException() &&
1995 name != vmSymbols::java_lang_ArrayIndexOutOfBoundsException() &&
1996 name != vmSymbols::java_lang_ArrayStoreException() &&
1997 name != vmSymbols::java_lang_ClassCastException() &&
1998 name != vmSymbols::java_lang_InternalError() &&
1999 name != vmSymbols::java_lang_NullPointerException()) {
2000 ResourceMark rm;
2001 fatal("default subgraph cannot have objects of type %s", subgraph_k->external_name());
2002 }
2003 }
2004 }
2005
2006 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = nullptr;
2007 int HeapShared::_num_new_walked_objs;
2008 int HeapShared::_num_new_archived_objs;
2009 int HeapShared::_num_old_recorded_klasses;
2010
2011 int HeapShared::_num_total_subgraph_recordings = 0;
2012 int HeapShared::_num_total_walked_objs = 0;
2013 int HeapShared::_num_total_archived_objs = 0;
2014 int HeapShared::_num_total_recorded_klasses = 0;
2015 int HeapShared::_num_total_verifications = 0;
2016
2017 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) {
2018 return _seen_objects_table->get(obj) != nullptr;
2019 }
2020
2021 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) {
2022 assert(!has_been_seen_during_subgraph_recording(obj), "sanity");
2023 _seen_objects_table->put_when_absent(obj, true);
2024 _seen_objects_table->maybe_grow();
2025 ++ _num_new_walked_objs;
2026 }
2027
2028 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) {
2029 log_info(cds, heap)("Start recording subgraph(s) for archived fields in %s", class_name);
2030 init_subgraph_info(k, is_full_module_graph);
2031 init_seen_objects_table();
2032 _num_new_walked_objs = 0;
2033 _num_new_archived_objs = 0;
2034 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses();
2035 }
2036
2037 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) {
2038 int num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() -
2039 _num_old_recorded_klasses;
2040 log_info(cds, heap)("Done recording subgraph(s) for archived fields in %s: "
2041 "walked %d objs, archived %d new objs, recorded %d classes",
2042 class_name, _num_new_walked_objs, _num_new_archived_objs,
2043 num_new_recorded_klasses);
2044
2045 delete_seen_objects_table();
2046
2047 _num_total_subgraph_recordings ++;
2048 _num_total_walked_objs += _num_new_walked_objs;
2049 _num_total_archived_objs += _num_new_archived_objs;
2050 _num_total_recorded_klasses += num_new_recorded_klasses;
2051 }
2052
2053 class ArchivableStaticFieldFinder: public FieldClosure {
2054 InstanceKlass* _ik;
2055 Symbol* _field_name;
2056 bool _found;
2057 int _offset;
2058 public:
2059 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) :
2060 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {}
2061
2062 virtual void do_field(fieldDescriptor* fd) {
2063 if (fd->name() == _field_name) {
2064 assert(!_found, "fields can never be overloaded");
2065 if (is_reference_type(fd->field_type())) {
2066 _found = true;
2067 _offset = fd->offset();
2068 }
2069 }
2070 }
2071 bool found() { return _found; }
2072 int offset() { return _offset; }
2073 };
2074
2075 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],
2076 TRAPS) {
2077 for (int i = 0; fields[i].valid(); i++) {
2078 ArchivableStaticFieldInfo* info = &fields[i];
2079 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
2080 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name);
2081 ResourceMark rm; // for stringStream::as_string() etc.
2082
2083 #ifndef PRODUCT
2084 bool is_test_class = (ArchiveHeapTestClass != nullptr) && (strcmp(info->klass_name, ArchiveHeapTestClass) == 0);
2085 const char* test_class_name = ArchiveHeapTestClass;
2086 #else
2087 bool is_test_class = false;
2088 const char* test_class_name = ""; // avoid C++ printf checks warnings.
2089 #endif
2090
2091 if (is_test_class) {
2092 log_warning(cds)("Loading ArchiveHeapTestClass %s ...", test_class_name);
2093 }
2094
2095 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, THREAD);
2096 if (HAS_PENDING_EXCEPTION) {
2097 CLEAR_PENDING_EXCEPTION;
2098 stringStream st;
2099 st.print("Fail to initialize archive heap: %s cannot be loaded by the boot loader", info->klass_name);
2100 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2101 }
2102
2103 if (!k->is_instance_klass()) {
2104 stringStream st;
2105 st.print("Fail to initialize archive heap: %s is not an instance class", info->klass_name);
2106 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2107 }
2108
2109 InstanceKlass* ik = InstanceKlass::cast(k);
2110 assert(InstanceKlass::cast(ik)->is_shared_boot_class(),
2111 "Only support boot classes");
2112
2113 if (is_test_class) {
2114 if (ik->module()->is_named()) {
2115 // We don't want ArchiveHeapTestClass to be abused to easily load/initialize arbitrary
2116 // core-lib classes. You need to at least append to the bootclasspath.
2117 stringStream st;
2118 st.print("ArchiveHeapTestClass %s is not in unnamed module", test_class_name);
2119 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2120 }
2121
2122 if (ik->package() != nullptr) {
2123 // This restriction makes HeapShared::is_a_test_class_in_unnamed_module() easy.
2124 stringStream st;
2125 st.print("ArchiveHeapTestClass %s is not in unnamed package", test_class_name);
2126 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2127 }
2128 } else {
2129 if (ik->module()->name() != vmSymbols::java_base()) {
2130 // We don't want to deal with cases when a module is unavailable at runtime.
2131 // FUTURE -- load from archived heap only when module graph has not changed
2132 // between dump and runtime.
2133 stringStream st;
2134 st.print("%s is not in java.base module", info->klass_name);
2135 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2136 }
2137 }
2138
2139 if (is_test_class) {
2140 log_warning(cds)("Initializing ArchiveHeapTestClass %s ...", test_class_name);
2141 }
2142 ik->initialize(CHECK);
2143
2144 ArchivableStaticFieldFinder finder(ik, field_name);
2145 ik->do_local_static_fields(&finder);
2146 if (!finder.found()) {
2147 stringStream st;
2148 st.print("Unable to find the static T_OBJECT field %s::%s", info->klass_name, info->field_name);
2149 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2150 }
2151
2152 info->klass = ik;
2153 info->offset = finder.offset();
2154 }
2155 }
2156
2157 void HeapShared::init_subgraph_entry_fields(TRAPS) {
2158 assert(HeapShared::can_write(), "must be");
2159 _dump_time_subgraph_info_table = new (mtClass)DumpTimeKlassSubGraphInfoTable();
2160 init_subgraph_entry_fields(archive_subgraph_entry_fields, CHECK);
2161 if (CDSConfig::is_dumping_full_module_graph()) {
2162 init_subgraph_entry_fields(fmg_archive_subgraph_entry_fields, CHECK);
2163 }
2164 }
2165
2166 #ifndef PRODUCT
2167 void HeapShared::setup_test_class(const char* test_class_name) {
2168 ArchivableStaticFieldInfo* p = archive_subgraph_entry_fields;
2169 int num_slots = sizeof(archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
2170 assert(p[num_slots - 2].klass_name == nullptr, "must have empty slot that's patched below");
2171 assert(p[num_slots - 1].klass_name == nullptr, "must have empty slot that marks the end of the list");
2172
2173 if (test_class_name != nullptr) {
2174 p[num_slots - 2].klass_name = test_class_name;
2175 p[num_slots - 2].field_name = ARCHIVE_TEST_FIELD_NAME;
2176 }
2177 }
2178
2179 // See if ik is one of the test classes that are pulled in by -XX:ArchiveHeapTestClass
2180 // during runtime. This may be called before the module system is initialized so
2181 // we cannot rely on InstanceKlass::module(), etc.
2182 bool HeapShared::is_a_test_class_in_unnamed_module(Klass* ik) {
2183 if (_test_class != nullptr) {
2184 if (ik == _test_class) {
2185 return true;
2186 }
2187 Array<Klass*>* klasses = _test_class_record->subgraph_object_klasses();
2188 if (klasses == nullptr) {
2189 return false;
2190 }
2191
2192 for (int i = 0; i < klasses->length(); i++) {
2193 Klass* k = klasses->at(i);
2194 if (k == ik) {
2195 Symbol* name;
2196 if (k->is_instance_klass()) {
2197 name = InstanceKlass::cast(k)->name();
2198 } else if (k->is_objArray_klass()) {
2199 Klass* bk = ObjArrayKlass::cast(k)->bottom_klass();
2200 if (!bk->is_instance_klass()) {
2201 return false;
2202 }
2203 name = bk->name();
2204 } else {
2205 return false;
2206 }
2207
2208 // See KlassSubGraphInfo::check_allowed_klass() - only two types of
2209 // classes are allowed:
2210 // (A) java.base classes (which must not be in the unnamed module)
2211 // (B) test classes which must be in the unnamed package of the unnamed module.
2212 // So if we see a '/' character in the class name, it must be in (A);
2213 // otherwise it must be in (B).
2214 if (name->index_of_at(0, "/", 1) >= 0) {
2215 return false; // (A)
2216 }
2217
2218 return true; // (B)
2219 }
2220 }
2221 }
2222
2223 return false;
2224 }
2225
2226 void HeapShared::initialize_test_class_from_archive(JavaThread* current) {
2227 Klass* k = _test_class;
2228 if (k != nullptr && ArchiveHeapLoader::is_in_use()) {
2229 JavaThread* THREAD = current;
2230 ExceptionMark em(THREAD);
2231 const ArchivedKlassSubGraphInfoRecord* record =
2232 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
2233
2234 // The _test_class is in the unnamed module, so it can't call CDS.initializeFromArchive()
2235 // from its <clinit> method. So we set up its "archivedObjects" field first, before
2236 // calling its <clinit>. This is not strictly clean, but it's a convenient way to write unit
2237 // test cases (see test/hotspot/jtreg/runtime/cds/appcds/cacheObject/ArchiveHeapTestClass.java).
2238 if (record != nullptr) {
2239 init_archived_fields_for(k, record);
2240 }
2241 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
2242 }
2243 }
2244 #endif
2245
2246 void HeapShared::init_for_dumping(TRAPS) {
2247 if (HeapShared::can_write()) {
2248 setup_test_class(ArchiveHeapTestClass);
2249 _dumped_interned_strings = new (mtClass)DumpedInternedStrings(INITIAL_TABLE_SIZE, MAX_TABLE_SIZE);
2250 init_subgraph_entry_fields(CHECK);
2251 }
2252 }
2253
2254 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
2255 bool is_full_module_graph) {
2256 _num_total_subgraph_recordings = 0;
2257 _num_total_walked_objs = 0;
2258 _num_total_archived_objs = 0;
2259 _num_total_recorded_klasses = 0;
2260 _num_total_verifications = 0;
2261
2262 // For each class X that has one or more archived fields:
2263 // [1] Dump the subgraph of each archived field
2264 // [2] Create a list of all the class of the objects that can be reached
2265 // by any of these static fields.
2266 // At runtime, these classes are initialized before X's archived fields
2267 // are restored by HeapShared::initialize_from_archived_subgraph().
2268 for (int i = 0; fields[i].valid(); ) {
2269 ArchivableStaticFieldInfo* info = &fields[i];
2270 const char* klass_name = info->klass_name;
2271 start_recording_subgraph(info->klass, klass_name, is_full_module_graph);
2272
2273 ContextMark cm(klass_name);
2274 // If you have specified consecutive fields of the same klass in
2275 // fields[], these will be archived in the same
2276 // {start_recording_subgraph ... done_recording_subgraph} pass to
2277 // save time.
2278 for (; fields[i].valid(); i++) {
2279 ArchivableStaticFieldInfo* f = &fields[i];
2280 if (f->klass_name != klass_name) {
2281 break;
2282 }
2283
2284 ContextMark cm(f->field_name);
2285 archive_reachable_objects_from_static_field(f->klass, f->klass_name,
2286 f->offset, f->field_name);
2287 }
2288 done_recording_subgraph(info->klass, klass_name);
2289 }
2290
2291 log_info(cds, heap)("Archived subgraph records = %d",
2292 _num_total_subgraph_recordings);
2293 log_info(cds, heap)(" Walked %d objects", _num_total_walked_objs);
2294 log_info(cds, heap)(" Archived %d objects", _num_total_archived_objs);
2295 log_info(cds, heap)(" Recorded %d klasses", _num_total_recorded_klasses);
2296
2297 #ifndef PRODUCT
2298 for (int i = 0; fields[i].valid(); i++) {
2299 ArchivableStaticFieldInfo* f = &fields[i];
2300 verify_subgraph_from_static_field(f->klass, f->offset);
2301 }
2302 log_info(cds, heap)(" Verified %d references", _num_total_verifications);
2303 #endif
2304 }
2305
2306 // Not all the strings in the global StringTable are dumped into the archive, because
2307 // some of those strings may be only referenced by classes that are excluded from
2308 // the archive. We need to explicitly mark the strings that are:
2309 // [1] used by classes that WILL be archived;
2310 // [2] included in the SharedArchiveConfigFile.
2311 void HeapShared::add_to_dumped_interned_strings(oop string) {
2312 assert_at_safepoint(); // DumpedInternedStrings uses raw oops
2313 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(string), "must be");
2314 bool created;
2315 _dumped_interned_strings->put_if_absent(string, true, &created);
2316 if (created) {
2317 _dumped_interned_strings->maybe_grow();
2318 }
2319 }
2320
2321 #ifndef PRODUCT
2322 // At dump-time, find the location of all the non-null oop pointers in an archived heap
2323 // region. This way we can quickly relocate all the pointers without using
2324 // BasicOopIterateClosure at runtime.
2325 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure {
2326 void* _start;
2327 BitMap *_oopmap;
2328 int _num_total_oops;
2329 int _num_null_oops;
2330 public:
2331 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap)
2332 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {}
2333
2334 virtual void do_oop(narrowOop* p) {
2335 assert(UseCompressedOops, "sanity");
2336 _num_total_oops ++;
2337 narrowOop v = *p;
2338 if (!CompressedOops::is_null(v)) {
2339 size_t idx = p - (narrowOop*)_start;
2340 _oopmap->set_bit(idx);
2341 } else {
2342 _num_null_oops ++;
2343 }
2344 }
2345 virtual void do_oop(oop* p) {
2346 assert(!UseCompressedOops, "sanity");
2347 _num_total_oops ++;
2348 if ((*p) != nullptr) {
2349 size_t idx = p - (oop*)_start;
2350 _oopmap->set_bit(idx);
2351 } else {
2352 _num_null_oops ++;
2353 }
2354 }
2355 int num_total_oops() const { return _num_total_oops; }
2356 int num_null_oops() const { return _num_null_oops; }
2357 };
2358 #endif
2359
2360 void HeapShared::count_allocation(size_t size) {
2361 _total_obj_count ++;
2362 _total_obj_size += size;
2363 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2364 if (size <= (size_t(1) << i)) {
2365 _alloc_count[i] ++;
2366 _alloc_size[i] += size;
2367 return;
2368 }
2369 }
2370 }
2371
2372 static double avg_size(size_t size, size_t count) {
2373 double avg = 0;
2374 if (count > 0) {
2375 avg = double(size * HeapWordSize) / double(count);
2376 }
2377 return avg;
2378 }
2379
2380 void HeapShared::print_stats() {
2381 size_t huge_count = _total_obj_count;
2382 size_t huge_size = _total_obj_size;
2383
2384 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2385 size_t byte_size_limit = (size_t(1) << i) * HeapWordSize;
2386 size_t count = _alloc_count[i];
2387 size_t size = _alloc_size[i];
2388 log_info(cds, heap)(SIZE_FORMAT_W(8) " objects are <= " SIZE_FORMAT_W(-6)
2389 " bytes (total " SIZE_FORMAT_W(8) " bytes, avg %8.1f bytes)",
2390 count, byte_size_limit, size * HeapWordSize, avg_size(size, count));
2391 huge_count -= count;
2392 huge_size -= size;
2393 }
2394
2395 log_info(cds, heap)(SIZE_FORMAT_W(8) " huge objects (total " SIZE_FORMAT_W(8) " bytes"
2396 ", avg %8.1f bytes)",
2397 huge_count, huge_size * HeapWordSize,
2398 avg_size(huge_size, huge_count));
2399 log_info(cds, heap)(SIZE_FORMAT_W(8) " total objects (total " SIZE_FORMAT_W(8) " bytes"
2400 ", avg %8.1f bytes)",
2401 _total_obj_count, _total_obj_size * HeapWordSize,
2402 avg_size(_total_obj_size, _total_obj_count));
2403 }
2404
2405 bool HeapShared::is_archived_boot_layer_available(JavaThread* current) {
2406 TempNewSymbol klass_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_CLASS);
2407 InstanceKlass* k = SystemDictionary::find_instance_klass(current, klass_name, Handle(), Handle());
2408 if (k == nullptr) {
2409 return false;
2410 } else {
2411 TempNewSymbol field_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_FIELD);
2412 TempNewSymbol field_signature = SymbolTable::new_symbol("Ljdk/internal/module/ArchivedBootLayer;");
2413 fieldDescriptor fd;
2414 if (k->find_field(field_name, field_signature, true, &fd) != nullptr) {
2415 oop m = k->java_mirror();
2416 oop f = m->obj_field(fd.offset());
2417 if (CompressedOops::is_null(f)) {
2418 return false;
2419 }
2420 } else {
2421 return false;
2422 }
2423 }
2424 return true;
2425 }
2426
2427 #endif // INCLUDE_CDS_JAVA_HEAP